restricted swig package

[Jack Howarth]

   I am running into a problem with my proposed pynmr
packaging...

http://trac.macports.org/ticket/21642

and the latest swig 1.3.40-1 packaging in 1.8.1. Previously
we built swig with python support and I leveraged that version
since swig is apparently missing from Xcode in Tiger. Would it
be possible to add variants to the swig package in macports to
provide the missing python support again or is there a way
in the Portfile to mark it as 10.5/10.6 only (which would be
required if I resorted to using the system swig from Xcode)?
                  Jack